Impeller with independent elastomeric blades and sealing means



March 28, 1961 F. H. P. SULLY 2,976,811

IMPELLER WITH INDEPENDENT ELASTOMERIC BLADES AND SEALING MEANS Filed July 28, 1958 FQAHK H. P. SULLY INVENTOR.

BY HIS ATTOQHEYS HAQQIS KIECH, POSTED. &' HAQIZIS tates IMPELLER WITH INDEPENDENT ELASTGMERIC BLADES AND SEALING MEANS Frank H. P. Sully, La Mirada, Calif, assignor to Jabsco Pump Company, Burbank, Calif.

Filed July 28, 1958, Ser. No. 751,310

7 Claims. (Cl. 103-117) The present invention relates in general to pumps and, more particularly, to pumps of the type having impellers provided with flexible, elastomeric blades or vanes extending generally radially outwardly from the hubs thereof, a primary object of the invention being to provide a pump impeller of this nature wherein the vanes and the hub are separate elements and wherein the vanes are detachably or removably connected to the hub at their inner edges.

A pump impeller of the foregoing construction has numerous advantages. For example, the hub may be made of a material, such as a synthetic resin, a metal. or the like, which is more compatible to the environment within the pump than the elastomeric material of the vanes. Thus, in a pump designed to handle fluids, such as hydrocarbons, which tend to cause the elastomeric material of the blades to swell in use, the hub may be made of a different material which will not be affected in this manner. In this connection, it should be pointed out that such swelling of the vanes is not particularly detrimental since they are sufficiently flexible or pliable to compensate therefor, but similar swelling of the hub, which is a relatively inflexible element even when made of an elastomeric material, would cause it to elongate and bear against the end walls of the impeller chamber with excessive force, which. would be detrimental from the standpoint of producing excessive friction, excessive wear of the end walls of the impeller chamber, and the like. Another advantage of making the hub of the impeller an element separate from the vanes is that the hub may readily be made shorter than the impeller chamber, which making the vanes at least as long as the impeller chamber, so that the ends of the hub do not bear against the end walls of the impeller chamber at all when the hub is centered relative to such end walls. This minimizes wear of the end walls of the impeller chamber, which is an important feature. Still another advantage of making. the impeller hub a separate element is that it permits the use of a material more susceptible to a satisfactory torque-transmitting connection with the shaft of the pump.

An important object of the invention is to provide a pump having an impeller of the foregoing nature and aren't having annular seals respectively engaging the end Walls of the impeller chamber, the ends of the hub and the ends of each vane adjacent the inner edge thereof, such seals cooperating with the end walls of the impeller chamber, the ends of the vanes and the ends of the hub to prevent communication at the ends of the impeller between the intervane spaces of the impeller. Such seals also maintain the ends of the hub out of engagement with the end walls of the impeller chamber when the length of the hub is less than that of the chamber.

A further object is to provide an impeller hub of the foregoing character having in its ends annular, and preferably circular, grooves intersecting the corresponding 5 ends of the vanes adjacent the inner edges thereof so that 2,976,811 Patented Mar. 28, 71961 the grooves are formed partially in the hub ends and partially in the blade ends, the annular seals, which are preferably ordinary O-rings, being disposed in such annular grooves, respectively.

The foregoing objects, advantages, features and re sults of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the art of elastomericvaned pumps, may be attained with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional View of one possible pump embodying the invention;

Fig. 2 is an end view of an impeller of the pump of Fig. l; and

Fig. 3 is an enlarged, fragmentary longitudinal sectional view of the impeller.

Referring particularly to Fig. l of the drawing, the numeral 10 designates a pump .housing which is shown as mounted on the housing of an electric motor 12, the latter having a shaft 14 which projects axially into the pump housing. Within the housing 10 is an impeller chamber 16 formed partially by a cylindrical bore 18 in the housing and partially by a cam 20 located at one side of the bore and held in place by a screw 22. The chamber 16 includes end walls 24 and 26 spaced apart axially thereof, the shaft 14 extending through the end wall 24 into the chamber 16 and terminating therewithin. The end wall 24 is formed by a removable wear plate in the particular construction illustrated, and the end wall 26 is formed by a removable cover held in place by screws 28.

Within the chamber 16 is an impeller 30 which includes a hub 32 telescoped over the shaft 14 and which includes flexible, elastomeric vanes 34 extending generally radially outwardly from the hub and having inner edges 36 detachably connected to the hub in a manner to be described hereinafter. In the particular construction illustrated, the hub 32 is shown as cup-shaped and as made of a suitable synthetic resin, or similar material, molded onto a deep, cup-shaped insert 38 comprising a sleeve 40 closed adjacent the closed end of the cup-shaped hub by a disc 42. The sleeve 40 is provided with an internal dimple or key 44 engaging a flat or keyway 46 on the shaft 14 to provide a torque-transmitting connection between the shaft and the hub 32. The sleeve 40 projects from the impeller chamber 16 along the shaft 14 in the direction of the-motor 12 and is engaged externally and axially outwardly of the impeller chamber by an annular sealing means 48 carried by the housing 10.

The inside diameter of the sleeve 40 slightly exceeds the diameter of the shaft 14 and the dimple 44 on the sleeve loosely engages the flat 46. The result of this structure is that the hub 32 fits the shaft 14 loosely so that it can be installed and removed readily by hand without the use of any special tools or equipment. The interconnection between the shaft 14 and the hub 32 which is shown in the drawing also completely isolates the shaft from the fluid handled by the pump, the closed 1 end of the hub 32 preventing contact between the shaft permitted to come in contact with the shaft, is prevented.

' It will be understood that the foregoing structure of the hub 32, the foregoing torque-transmitting connection plished by making the inner edges 36 of the vanes 34 dovetailed in cross section and disposing them in external longitudinal grooves 59 of dovetail cross section in the hub 32. With this construction, the vanes 34 may be mounted on and removed from the, hub 32 readily merely by sliding the dovetailed inner edges 36 thereof longitudinally into and out of the dovetail grooves 50 in the hub.

The widths of thevanes 34, i.e., the radial dimensions thereof, are such that the outer edges 52 thereof engage the. peripheral wall of the impeller chamber 16 in a fluid tight manner, the characteristic pumping action of a pump of this type occurring as the outer edges 52 of the vanes traverse the inner surface of the cam 20, as is well known in the art. The lengths of the vanes 34, i.e., the axial dimensions thereof, are at least equal to the spacing of the end walls 24 and 26 of the impeller chamber 16 so that the ends of the vanes engage the end walls of the impeller chamber in a fluid-tight manner. In the preferred form of the invention, the ends of the hub 32, which are identified by the reference numerals 54 and 56, respectively, are out of engagement with the end walls 24 and 26, respectively, to minimize friction, to minimize wear of the end walls, and the like.

In order to prevent fluid communication between the intervane spaces of the impeller 30- at the ends of the impeller, the invention provides annular seals, preferably ordinary O-rings 58 and 60, respectively engaging the end walls 24 and 26, the hub ends 54 and56, and the corresponding ends of the inner edges 36 of the vanes 34,

which closethe inner sides of the intervene spaces. The O-rings 58 and 60 also maintain the respective hub ends 54 and 56 out of engagement with the respective end walls 24 and 26.

The O-rings 58 and 60 are disposed in annular grooves 62. and 64, respectively, which are formed in the hub ends 54 and 56, respectively, and which intersect the corresponding ends of the inner edges 36 of the vanes 34, these grooves thus being formed partially in the ends of the vanes at the inner edges thereof. From another point of view, each end of each vane 34 is notched at its inner edge 36, as best shown in Fig. 3 of the drawing, to receive the corresponding O-ring.

Thus, with the foregoing construction, even though the ,hub 32 is shorter than the impeller chamber 16 and is formed of a material which would not form a fluid-tight seal with the end walls 24 and 26 of the chamber even if it did engage them, no leakage from one intervane space to the next can occur due to the sealing engagement of theO-rings 53 and 60 with the respective vane ends, the respective hub ends 54 and 56 and the respective end walls 24 and 26, whichis an important feature of the invention. Further, the O-rings 58 and 60' serve to prevent the hub ends 54 and 56 from contacting the end walls 24 and 26 of the impeller chamber 16. An-

other advantage of this construction is that any lack of coaxiality between the shaft 14- and the bore 18 in the pump housing It is compensated for by the elasticity of the O-rings. For example, even if the shaft 14 is bent, the O-rings58 and 60 will compensate for the resulting "wobble of the impeller 30, the vanes 34, of course, being sufliciently flexible to take care of such a condition.

After the pump has been in operation long enough to 4 wear the vanes 34 and/or the O-rings 58 and 60 excessively, these elements may readily be replaced.

Although an exemplary embodiment of the invention has been disclosed herein for purposes of illustration, it will be understood that various changes, modifications, and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims which follow.

I claim:

1. In a pump, the combinationof: a pump housing providing an impeller chamber having axially spaced end walls; a shaft extending through one of said end walls into said chamber; an: impeller in said chamber and including a hub telescoped over said shaft, said impeller further including flexible, elastomeric vanes which are separate from each other and from said hub, said vanes extending generally radially outwardly from said hub and having inner edges in engagement with said hub, the length of said hub being less than the spacing of said end walls of said chamber so that the ends of said hub are out of engagement with said end walls, respectively, when said hub is centered relative to said end walls, the length of each of said vanes being at least equal to the spacing of said end Walls so that the ends thereof are in engagement with said end Walls, respectively; means removably connecting said inner edges of said vanes to said hub; two annular seals within said chamber and respectively engaging said end walls, said ends of said hub and said ends of each of said vanes adjacent said inner edge thereof, said seals maintaining said ends of said hub out of engagement with said end walls; and means interconnecting said hub and said shaft for transmitting rotation of said shaft to said hub.

2. In a pump, the combination of: a pump housing providing an impeller chamber having axially spaced end walls; a shaft extending through one of said end walls into said chamber; an impeller in said chamber and including a hub telescoped over said shaft, said impeller further including flexible, elastomeric vanes which are separate from each other and from said huh, said vanes extending generally radially outwardly from said hub and having inner edges in engagement with said hub, the length of said hub being less than the spacing of said end walls. of said chamber so that the ends of said hub are out of engagement with said end WdllS, respectively, when said hub is centered relative to said endwalls, the length of each of said vanes being at least equal to the spacing of said end walls so that the ends thereof are in engagement with said end walls, respectively; means removably connecting said inner edges of said vanes to said. hub; two annular seals respectively carried by the ends of said impeller and respectively engaging said end walls, said ends of said hub and said ends of each of said, vanes adjacent said inner edge thereof, said seals maintaining said ends of said hub out ofengagement with said end walls; and means interconnecting said hub and said shaft for transmitting rotation of said shaft to said hub.

33. In a pump, the combination: of a pump housing providing an impeller chamber having axially spaced end walls; a shaft extending through one of said end walls into said chamber; an impeller in said chamber and in cluding a'hub telescoped over said shaft, said impeller further including flexible, elastomeric vanes which are separate from each rther and from said hub, said vanes extending generally radially outwardly from said hub and having inner edges in engagement with said hub, the length of said hub being less than the spacing of said end walls of said chamber so that the ends of said hub are out of engagement with said end walls, respec tively, when saidhub is centered relative to said end walls, the length of each of 'said vanes being at least equal to the spacing of said end walls so that the ends h p are i ngag ment with saidend walls, respectively, each of said ends of said hub having an annular groove therein which intersects the corresponding ends of said vanes adjacent said inner edges thereof; means removably connecting said inner edges of said vanes to said hub; two annular seals respectively disposed in said annular grooves and respectively engaging said end walls, said ends of said hub and said ends of each of said vanes adjacent said inner edge thereof, said seals maintaining said ends of said hub out of engagement with said end walls; and means interconnecting said hub and said shaft for transmitting rotation of said shaft to said hub.

4. In a pump impeller, the combination of: a hub having axially spaced ends; flexible, elastomeric vanes which are separate from each other and from said hub, said vanes extending generally radially outwardly from said hub and being in engagement with said hub along inner edges thereof, the lengths of said vanes exceeding the lengths of said hub so that the ends of said vanes project axially beyond said ends of said hub, each of said ends of said hub having therein an annular groove which intersects the corresponding ends of said vanes adjacent said inner edges thereof; means removably connecting said inner edges of said vanes to said hub; and two annular seals respectively disposed in said annular grooves and respectively engaging said ends of said hub and said ends of each of said vanes adjacent said inner edge thereof.

5. A pump impeller according to claim 4 wherein said inner edges of said vanes are dovetailed into said hub.

6. In a pump impeller, the combination of: a hub having axially spaced ends; flexible, elastomeric vanes which are separate from each other and from said hub, said vanes extending generally radially outwardly from said hub and being in engagement with said hub along inner edges thereof, each of said ends of said huh having therein an annular groove which intersects the corresponding ends of said vanes adjacent said inner edges thereof; means removably connecting said inner edges of said vanes to said hub; and two annular seals respectively disposed in said annular grooves and respectively engaging said ends of said hub and said ends of each of said vanes adjacent said inner edge thereof.

7. In a pump, the combination of: a pump housing providing an impeller chamber having axially spaced end walls; a shaft extending through one of said end walls into said chamber; an impeller in said chamber and including a hub telescoped over said shaft, said impeller further including flexible, elastomeric vanes which are separate from each other and from said hub, said vanes extending generally radially outwardly from said hub and having inner edges in engagement With said hub; means removably connecting said inner edges of said vanes to said hub; two annular seals within said chamber and respectively engaging said end Walls, said ends of said hub and said ends of each of said vanes adjacent said inner edge thereof; and means interconnecting said hub and said shflt for transmitting rotation of said shaft to said hub.

References Cited in the file of this patent UNITED STATES PATENTS 2,237,451 Samuels Apr. 8, 1941 2,460,952 Simer et al. Feb. 8, 1949 2,493,602 Sterrett Jan. 3, 1950 2,558,970 Lipfert July 3, 1951 2,644,402 Lehman July 7, 1953 2,732,126 Smith Ian. 24, 1956 2,782,723 Doble et al Feb. 26, 1957 2,843,049 Sherwood July 15, 1958 

